Beyond the Headache: Autonomic Reflex Dysfunction and Sensory Hypersensitivity Contribute to Orthostatic Intolerance in Migraine

TL;DR

The study shows that migraine patients often experience orthostatic intolerance due to autonomic dysfunction and heightened sensory sensitivity.

Contribution

The paper identifies two distinct mechanisms for orthostatic intolerance in migraine patients: cardiovascular and sensory hypersensitivity.

Findings

83% of migraine patients experienced orthostatic intolerance during tilt testing.

POTS was the most common cause of abnormal cardiovascular responses to tilt.

Sensory hypersensitivity was linked to higher fibromyalgia scores and overlapping pain conditions.

Abstract

We sought to determine: 1.) the relationship between headache frequency and autonomic reflexes, and 2.) mechanisms underlying orthostatic intolerance (OI) in patients with migraine.

Adults with migraine (N = 30) underwent autonomic function tests summarized as the Composite Autonomic Severity Score (CASS) and vagal/adrenergic baroreflex sensitivity (BRS-V/A). Postural Orthostatic Tachycardia Syndrome (POTS) and orthostatic hypotension/hypertension were diagnosed during tilt table testing. A cold pressor test (CPT) evaluated sympathetic vasomotor function. Participants completed the Migraine Disability Assessment (MIDAS), the 2011 Fibromyalgia (FM) Survey Criteria, chronic overlapping pain condition (COPC) screener, and Compass-31.

Monthly headache days correlated with CASS (p = 0.001), BRS-V (p < 0.001), and the systolic blood pressure response to CPT (p = 0.003) in the expected direction with increasing ANS reflex dysfunction correlating to increasing number of headache days. During tilt testing, OI was prevalent (25/30; 83%) and reported by all patients with chronic migraine. An abnormal cardiovascular response to tilt was present in the majority (63%) of which POTS was the most common etiology (56.2%). Patients reporting OI during tilt table testing despite a normal cardiovascular response (33%) had higher FM scores (15.8 ± 3.6 vs. 7.5 ± 4.6; p < 0.01) and a greater prevalence of non-headache COPCs (88.8% versus 20.0%, p = 0.02), compared to participants who were asymptomatic during tilt.

There are two etiologies of OI in patients with migraine: 1.) an abnormal cardiovascular response to tilt (concordant OI) and, 2.) sensory hypersensitivity (discordant OI).

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